Spin excitations of the correlated semiconductor FeSi probed by THz radiation

V. V. Glushkov, B. P. Gorshunov, E. S. Zhukova +5

By direct measurements of the complex optical conductivity $\sigma (\nu )$ of FeSi we have discovered a broad absorption peak centered at frequency ${\nu }_0(4.2K)\approx 32c{m}^{-1}$ that de…